#define _CRT_SECURE_NO_WARNINGS

//DP34 【模板】前缀和

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n, q;
    cin >> n >> q;
    vector<int> arr(n+1);
    for(int i = 1; i <= n; i++)
    {
        cin >> arr[i];
    }
    //预处理出一个前缀和数组
    vector<long long> dp(n+1);
    for(int i = 1;i <= n; i++)
    {
        dp[i] = dp[i-1] + arr[i];
    }
    int l = 0, r = 0;
    while(q--)
    {
        cin >> l >> r;
        cout << dp[r] - dp[l - 1] << endl;
    }
    return 0;
}